Epigallocatechin gallate eye drops protect against ultraviolet B–induced corneal oxidative damage in mice

Purpose Ultraviolet B (UVB) radiation from sunlight is a known risk factor for human corneal injury. The aim of the present study was to investigate the protective effects of green tea polyphenol epigallocatechin gallate (EGCG) on UVB radiation–induced corneal oxidative damage in male imprinting control region (ICR) mice. Methods Corneal oxidative damage was induced by exposure to UVB radiation at 560 μW/cm2. The animals received 0%, 0.1%, and 0.01% EGCG eye drops at a 5 mg/ml dose, twice daily for 8 days. Corneal surface damage was graded according to smoothness and the extent of lissamine green staining. Corneal glutathione (GSH), thiobarbituric acid-reactive substances (TBARS), and protein carbonyl levels, as well as superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px), and glutathione reductase (GSH-Rd) activity in the cornea, were measured to monitor corneal injury. Results UVB radiation caused significant damage to the corneas, including apparent corneal ulceration and severe epithelial exfoliation, leading to a decrease in SOD, catalase, GSH-Px, GSH-Rd, and GSH activity in the cornea. However, the corneal TBARS and protein carbonyls increased compared with the control group. Treatment with EGCG eye drops significantly (p